High Idle

[slickers111]

Last issue on the car.

Fresh rebuild on the motor. Let it idle for about 30 minutes, and took it for a short ride.

At cold start, it idles at 1,900 rpm. then backs down to 1,400. If I turn the wheels all the way right or left, the idle drops to 1,200 only cause the draw.

Ive tried adjusting the BISS. Opening it up moves idle +100 rpm. All the way shut it still sits at 1,400-1500.

Its a 97 motor on a 96 ECU. Emissions deleted, A/C gone if that matters. TB vac ports blocked off. EGR is still on, 2 ports on that are vented. J-pipe vac line is just on the intake before the turbo till I tap into the j-pipe.

Running on stock BCS.

Dont really wanna mess with much till I got a good idea of what im doing.

 

[newtodsm97gst]

I'm having the same problem, newly rebuilt engine. put in 1g nt tb, new ISC, 2g TPS but my idle surge goes up to 2700 rpm. no boost leak, no idea whats next..

 

[slickers111]

I think the TPS may be outta whack, but I dont wanna go in messing with stuff without some back up.
Im also gonna take apart the throttle system and make sure its all clean.

 

[2g spyder eclipse]

Brion is a newb

 

[WES_393]

Last issue on the car.

Fresh rebuild on the motor. Let it idle for about 30 minutes, and took it for a short ride.

At cold start, it idles at 1,900 rpm. then backs down to 1,400. If I turn the wheels all the way right or left, the idle drops to 1,200 only cause the draw.

Ive tried adjusting the BISS. Opening it up moves idle +100 rpm. All the way shut it still sits at 1,400-1500.

Its a 97 motor on a 96 ECU. Emissions deleted, A/C gone if that matters. TB vac ports blocked off. EGR is still on, 2 ports on that are vented. J-pipe vac line is just on the intake before the turbo till I tap into the j-pipe.

Running on stock BCS.

Dont really wanna mess with much till I got a good idea of what im doing.

For one, a new engine shouldn't idle for long periods. I would recommend looking up the "Motoman Method" for break in and following it ASAP.

High idle is typically caused by a vacuum/boost leak right at or after the throttle body. Have you tried running a boost leak test and using soapy water to find leaks? If not then I would do so with the leak tester at the throttle body elbow and just focus on that area first. Have you removed the coolant lines for the throttle body? If so, did you completely close the Fast Idle Air Valve?

You also shouldn't adjust the BISS screw blindly. It won't adjust the idle unless you lock the ISC position. Otherwise the ISC is just going to counteract any adjustments you make.

And lastly, if your talking about the line that goes from the J-pipe to the BCS, that's the wastegate actuator line which needs positive pressure to open the wastegate. If you have it running to the intake before the compressor

 

[mjdarg]

Check your sensors on your TB to make sure they are all in working order (TPS, ISC, idle stop switch). If you took your throttle plate off make sure your throttle is fully closing. Check proper slack in throttle cable.

 

[slickers111]

For one, a new engine shouldn't idle for long periods. I would recommend looking up the "Motoman Method" for break in and following it ASAP.

High idle is typically caused by a vacuum/boost leak right at or after the throttle body. Have you tried running a boost leak test and using soapy water to find leaks? If not then I would do so with the leak tester at the throttle body elbow and just focus on that area first. Have you removed the coolant lines for the throttle body? If so, did you completely close the Fast Idle Air Valve?

You also shouldn't adjust the BISS screw blindly. It won't adjust the idle unless you lock the ISC position. Otherwise the ISC is just going to counteract any adjustments you make.

And lastly, if your talking about the line that goes from the J-pipe to the BCS, that's the wastegate actuator line which needs positive pressure to open the wastegate. If you have it running to the intake before the compressor

It wasnt at idle for the 30 straight. 30 total. 7-10 minute periods.

After the emissions delete, the only lines I have are FPR to intake T'd for gauge. Intake to BOV T-d to wastegate. Intake to Brake booster. Then the mis placed BCS to intake pipe.

The line for the BCS is being changed. I couldnt get a Tap for the j-pipe before.

Ill look up a "build your own BLT" and see where it shows. Only gaskets/seals that arent new are the fuel injector seats in the head.

I did have the coolant lines all disconnected. Ill look up how to close the FIAV.

 

[zachwilliams02]

For one, a new engine shouldn't idle for long periods. I would recommend looking up the "Motoman Method" for break in and following it ASAP.

High idle is typically caused by a vacuum/boost leak right at or after the throttle body. Have you tried running a boost leak test and using soapy water to find leaks? If not then I would do so with the leak tester at the throttle body elbow and just focus on that area first. Have you removed the coolant lines for the throttle body? If so, did you completely close the Fast Idle Air Valve?

You also shouldn't adjust the BISS screw blindly. It won't adjust the idle unless you lock the ISC position. Otherwise the ISC is just going to counteract any adjustments you make.

And lastly, if your talking about the line that goes from the J-pipe to the BCS, that's the wastegate actuator line which needs positive pressure to open the wastegate. If you have it running to the intake before the compressor

i second the vacuum leak. is your blow off valve vented? or recirculated. when you did the egr blockoff did you block off all of the ports?. take a can of carb cleaner and go to town, spray all over any intake component and if the rpms drop then rise or you get an erratic idle that is your leak

 

[slickers111]

i second the vacuum leak. is your blow off valve vented? or recirculated. when you did the egr blockoff did you block off all of the ports?. take a can of carb cleaner and go to town, spray all over any intake component and if the rpms drop then rise or you get an erratic idle that is your leak

A vented BOV would not be the reason for the high idle.

The ports on the EGR are vented. As in left open like in the picture.

And seeing as I have no air compressor, I was going to try the smoke BLT, then the water and soap while running.

 

[mjdarg]

I did have the coolant lines all disconnected. Ill look up how to close the FIAV.

This sounds like the problem. You can either tighten the FIAV all the way in or use a block off plate. I ended up just making one from 16 gauge steel and its worked great.

 

[slickers111]

Would you be able to tell me how to just close it, and make it go away?

I have a whole $4 left after the rebuild. :/

 

[edged1g]

Would you be able to tell me how to just close it, and make it go away?/

http://www.dsmtuners.com/forums/articles-intake-exhaust/320951-fiav-adjustment-disable.html

 

[jmfc15]

This sounds like the problem. You can either tighten the FIAV all the way in or use a block off plate. I ended up just making one from 16 gauge steel and its worked great.

Ive learned that an idle issue is generally a vacuum leak/ coolant issue. Can any senior members explain why car companies have coolant running near the throttle body? IE the purpose of a FIAV or FIT Valve on Hondas? Any insight on what happens when you bypass it?

 

[AWDtalontsi96]

Ive learned that an idle issue is generally a vacuum leak/ coolant issue. Can any senior members explain why car companies have coolant running near the throttle body? IE the purpose of a FIAV or FIT Valve on Hondas? Any insight on what happens when you bypass it?

There are many reasons why companies run coolant throw the throttle body. but the main reason is so in cold weather the TB plate does freeze up and get stuck either closed or open. in cold weather in coming air with a lot of moisture can end up condensing and then freezing.

 

[WES_393]

Any insight on what happens when you bypass it?

The FIAV adjusts with coolant temperature, like a thermostat. As the coolant gets hotter the valve lets less air bypass the throttle plate. Without coolant running to the throttle body the FIAV won't shut when the car warms up resulting in too much air bypassing the throttle plate, which can cause idle and stalling issues. The solution is to adjust the FIAV so that it's always closed.